The present invention relates to a stencil printer or similar printer.
Various kinds of papers have customarily been used with a stencil printer or similar printer. Thin papers, for example, include rough printing papers and fine 45 kg papers. Papers of standard thickness (sometimes referred to as standard papers hereinafter) include copy papers, mediumquality papers, fine quality 55 kg papers, recycled papers, and fine papers for stencil printers. Further, thick papers include drawing papers, postcards, envelopes, fine 135 kg papers, and fine 160 kg papers.
To guarantee the paper feeding and discharging ability of the printer, i.e., to reduce troubles relating to paper transport as far as possible, it is necessary to variably set optimal transport conditions at the paper feed section, paper discharge section and other various sections of the printer in accordance with the kind of papers including thickness and size. This is because particular optimal transport conditions exist for each kind of papers. Necessary transport conditions to be set include a paper feed pressure, a paper separation pressure, a jump board angle and a side fence position relating to paper discharge, and a tray angle relating to paper feed. The troubles relating to paper transport are typified by the simultaneous feed of two or more papers (sometimes referred to as overlap feed hereinafter), the failure of paper feed (sometimes referred to as feed failure hereinafter), and jams occurring at the paper feed section and paper discharge section.
It is a common practice for the operator, user or serviceman (operator hereinafter) to determine the kind of papers by confirming the thickness and size of papers by eye, and manually switch a pick-up roller pressure, a separation pad pressure, a jump board angle and so forth in such a manner as to set up optimal transport conditions for the papers.
In practice, however, it is extremely difficult for an ordinary or untrained operator to determine or set optimal transport conditions paper by paper. For this reason, the manual switching function available with the printer has been rarely used, resulting in the troubles relating to paper transport.
Moreover, when any one of the troubles occurs, the operator is often simply perplexed and cannot see or execute an optimal troubleshooting measure. Although an operation manual attached to the printer describes measures for dealing with various kinds of troubles specifically, it is not readable for ordinary operators and is, if readable, troublesome and time-consuming to read.
Technologies relating to the present invention are disclosed in, e.g., Japanese Patent Publication No. 5-32296, Japanese Patent Laid-Open Publication Nos. 9-30714, 9-235033 (corresponding to U. S. Ser. No. 08/719,960, filed Sep. 24, 1996) and 10-139191 (corresponding to U.S. Ser. No. 08/925,648, filed Sep. 9, 1997), Japanese Utility Model Publication Nos. 4-23862 and 5-18342, and Japanese Patent Laid-Open Publication Nos. 9-20436, 8-259099, 9-26678, and 2-144335.